Spinal Rod Link Reducer

ABSTRACT

The present invention includes a rod link reducer of a spinal fixation system that includes a first and a second spinal rod manipulator; a first spinal rod manipulator joint connected to the first spinal rod manipulator and a second spinal rod manipulator joint connected to the second spinal rod manipulator; a first and a second translatable transverse shaft connected to the first and second joints, respectively; and a universal reducer connected to both the first and second translatable transverse shafts, wherein the universal reducer, the shafts and the linkers provide movement and temporary fixation of a spine that has been manipulated into a final position during spinal surgery.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 61/025,761, filed Feb. 2, 2008, and to U.S. Provisional ApplicationSer. No. 61/080,162 filed Jul. 11, 2008, the contents of both of whichis incorporated by reference herein in its entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to the field of bone fixation,and more particularly, to a novel rod link reducer for use during thecorrection of mild to severe spinal deformities.

STATEMENT OF FEDERALLY FUNDED RESEARCH

None.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is describedin connection with pedicle screws.

In rigid severe spine deformity with coronal or sagittal decompensation,translation of the spinal column is necessary for restoration of trunkbalance as well as deformity correction. However, the conventionalcorrection methods, such as posterior correction only or anteriorrelease and posterior instrumentation, are usually unsatisfactory.Therefore, a more aggressive approach, such as reconstructivetechniques, is necessary. In 1922, Maclennan¹ first illustratedvertebrectomy and demonstrated an apical resection from a posterior-onlyapproach with postoperative casting for the treatment of severescoliosis. Several authors²⁻⁸ have subsequently reported theirexperience with vetebrectomy, mostly for congenital scoliosis. In 1987,Bradford⁹ performed both anterior and posterior vertebral columnresection (VCR) with spinal shortening and posterior instrumentation andfusion demonstrating excellent restoration of coronal with relativelyfew complications. Leatherman⁶ introduced a two-stage anterior andposterior correction procedure for congenital spinal deformity. Bradfordand Bochie-Adjei¹⁰ also reported a single stage anterior and posteriorresection of hemivertebra and spinal arthordesis. However, theanterior-posterior vertebral column resection (VCR) has disadvantagessuch as long operative time, potential significant blood loss, and riskof intraoperative neurologic impairment due to the spinal column segmentinstability during the resection and the correction procedure.

In 2002, Suk¹¹⁻¹³ introduced a technique of a single posterior approachto perform VCR (PVCR) that offered significant advantages over thecombined anterior-posterior VCR. The surgery consisted of temporarystabilization of the vertebral column with segmental pedicle screwfixation, resection of the vertebral column at the apex of the deformityvia the posterior route followed by gradual deformity correction andglobal fusion. In the surgical technique, multiple pedicle screws wereutilized proximal and distal to the vertebral resection to securely fixthe spine prior to any bony resection. Provisional single rod placementis performed during the bony resection to prevent sudden spinal columntranslations which may result in spinal cord injury. The vertebralcolumn resection and deformity correction were carried out either byexchanging the temporary precontoured rods one by one or by in situ rodbending. However, these technique have a number of disadvantages: 1) therisk of intraoperative mishaps due to the instability resulting fromexchanging the temporary rods may produce spinal cord injury; 2)limitation in deformity correction secondary to a “one-time” correctionmaneuver utilized using the Suk technique; 3) short segment fixationusing the provisional rods since multiple exchanges prevent long rodutilization; and 4) additional surgical time necessary with multipleremoval and insertion of the temporary provisional rods.

One such fixation system is taught in U.S. Pat. No. 7,220,262, issued toHynes. Briefly, the spinal fixation system and related methods includepedicle screws secured in two columns, one along each side of the spine.Cross support rods have ends connected to pedicle screw heads. Alongitudinally extending rod is supported on the cross supports andrecessed in the cavity created by removal of portions of spinousprocesses, providing a reduced profile of the installed construct.Several types of cross supports are shown such as: arms from the screwsinward to rings or yokes connecting the longitudinal rod; cross rodswith ends connected to the screws and having centrally-located yokes forthe longitudinal rod; cross rods with articulating longitudinal rodportions fixed or swiveled to them. These cross rods may have endportions angled posterior toward anterior to accommodate lateralpositioned pedicle screws, but shorter cross rods without angled endportions enable medialized pedicle screw orientation.

United States Patent Application No. 20070270810, filed by Sanders isdirected to a pedicle screw spinal rod connector arrangement. Briefly, apedicle screw spinal rod connector arrangement is provided that includesin a body having an opening for mounting a head of an inserted pediclescrew. A bracket connected with the body forms a lateral restraint. Abridge is connected with and extends over the body. A spinalrod-receiving slot is provided between the bridge and the bracket. Theconnector arrangement also has a wedge axially offset from the pediclescrew moveable downward by a setscrew mounted with the bridge. The wedgeimparts a locking force on the pedicle screw head and a generallylateral locking force on the spinal rod.

Yet another example is shown in United States Patent Application No.20070233062, filed by Berry for a pedicle screw system with offsetstabilizer rod. In this example, an improved pedicle screw system isprovided with an offset stabilizer rod for the internal fixation of thespine. The pedicle screw system includes at least two multi-anglepedicle screw units adapted for anchored securement to patient bone, andan elongated stabilizer rod extending therebetween. Each pedicle screwunit includes a bone screw associated with an anchor bracket defining alaterally offset and upwardly open channel or trough for receiving andsupporting the stabilizer rod. A securement member such as a set screwis fastened to the anchor bracket for compressively retaining thestabilizer rod within the bracket channel or trough. The securementmember may also bear against the associated bone screw for compressivelyretaining the screw in position relative to the anchor bracket.

SUMMARY OF THE INVENTION

The present invention solves various problems of current spinal fixationsystems and the control of the positioning of temporary rod duringspinal surgery. The present invention allows the surgeon to stabilizethe spine, effectively derotate the spine, safely translate the spineand when required easily derotate and translate the spine to treatspinal deformities.

The present inventors recognized there and other disadvantages of thecurrent implant strategies used during Posterior Vertebral ColumnResection (PVCR) by designing a new pedicle screw posteriorinstrumentation system. The present invention includes screws, methods,kits and systems that provide a safer, easier and better correction, aswell as shorter operation time method for the PVCR of the severe spinaldeformity. The present invention takes advantage of the top-loading andside-loading current designs as well as a universal connecting link toprovide three-dimensional correction. These components provide: 1)continued stabilization of the spine during bony resection as well ascorrection; 2) allow for controlled correction of the spine using bothrods; and 3) provide the ability to place the permanent rods while thelong provisional rod is in places so instability is not created.

The present invention includes: 1) a pedicle screw with a screw headthat can receive two rods. The bone screw head includes tworod-receivers. One receiver member is basic “U” shape (top-loadingcomponent) that extends from the top of the screw head to receive atemporary rod. Another receiver member has a basic “C” shape(side-loading component) that is inferior to the first receiver. Thesecond receiver receives a final rod. There is also a breakawaymechanism between the first and second apertures so that the firstaperture can be removed while the final rod is fixed; 2) rod-linkreducer has a basic “H” shape that rigidly links and locks the temporaryrods, which allows attachment to the rod at any orientation in thecoronal, sagittal, and transverse planes so as to make compression,distraction, derotation and cantilever method; 3) reduction handleconnects with the rod-link reducer; and 4) 5.5 mm diameter rod. For thePVCR of severe spinal deformity, this instrumentation system wouldprovide: 1) better maintenance of spinal stability throughout thesurgical procedure to reduce risk of the spinal cord injuries; 2) morereliable reconstruction of the vertebral column; 3) better and easiercorrection of the deformity; and 4) shorter operative time.

More particularly, the present invention includes a rod link reducer fora spinal fixation system, the rod link reducer includes a first and asecond spinal rod manipulator; a first spinal rod manipulator jointconnected to the first spinal rod manipulator and a second spinal rodmanipulator joint connected to the second spinal rod manipulator; afirst and a second translatable transverse shaft connected to the firstand second joints, respectively; and a universal reducer connected toboth the first and second translatable transverse shafts, wherein thereducer, the shafts and the linkers provide movement and temporaryfixation of a spine that has been manipulated into a final positionduring spinal surgery. In one aspect, the spinal rod manipulator isfurther defined as comprising a handle and a rod attachment fixationpoint, wherein the rod attachment fixation point at least partiallysurrounds a rod with a semi-permanent fastener. In another aspect, thefirst, the second or both the first and second translatable transverseshafts connects to the universal reducer and are capable of sliding toincrease or decrease the distance between the first and second joints.The universal reducer can be, for example, a ball joint, a universaljoint, a pivot, a slot, a collar, a bearing, a dove-tail, a ball-joint,a gimbal, a level, or a sleeve that permits movement of the translatabletransverse shafts in two or more dimensions. In another aspect, theuniversal reducer may also includes a fastener that semi-permanentlyfixes the position of the reducer in relation to the first, the secondor both translatable transverse shafts. The first and second joints mayeach also includes an independent fastener that semi-permanently fixesthe relative position of the first spinal rod manipulator to the firsttranslatable transverse shaft, the second spinal rod manipulator to thesecond translatable transverse shaft or both the first and second spinalrod manipulator to the first and second translatable transverse shafts,respectively. Any component of the rod link reducer comprises titanium,stainless steel, spring steel, aluminum, Niobium and alloys thereof,carbon fiber, ceramics, polymers, composites or combinations thereof.

In another embodiment, the present invention includes a method ofcorrecting a spinal deformity by fastening two or more pedicle screwinto two or more vertebra; interconnecting the pedicle screws with twoor more temporary rods; connecting a of link reducer between thetemporary rods, the rod link reducer having a first and a second spinalrod manipulator; a first spinal rod manipulator joint connected to thefirst spinal rod manipulator and a second spinal rod manipulator jointconnected to the second spinal rod manipulator; a first and a secondtranslatable transverse shaft connected to the first and second joints,respectively; and a universal reducer connected to both the first andsecond translatable transverse shafts, wherein the reducer, the shaftsand the linkers provide movement and temporary fixation of a spine thathas been manipulated into a final position during spinal surgery. Next,the user correct the position of the spine by manipulating the temporaryrods attached to the pedicle screws; interconnects the pedicle screwswith a permanent fixation rod; and finally removes the temporary rod.One example of a pedicle screw for use with the present invention mayinclude a bone fastener and a rod coupling head, the rod coupling headcomprising a lower and an upper rod coupling: the lower rod couplingincluding a lateral rod opening adapted to receive a permanent rod; anangled bore extends into the lateral rod opening; and a permanent rodfastener in the angled bore to engage a permanent rod in the lateral rodopening; and a upper rod coupling having: an upper rod opening adaptedto receive a temporary rod, wherein the upper rod opening is formed toreceive a temporary rod fastener, wherein the upper rod coupling isdetachable from the lower rod coupling at a transition, wherein atemporary rod is temporarily affixed into the upper rod opening during abone realignment and a permanent rod is positioned in the lateral rodopening and engaged by the permanent rod fastener upon final bonealignment. In one aspect, the spinal rod manipulator is further definedas comprising a handle and a rod attachment fixation point, wherein therod attachment fixation point at least partially surrounds a rod with asemi-permanent fastener. In another aspect, the first, the second orboth the first and second translatable transverse shafts connects to theuniversal reducer and are capable of sliding to increase or decrease thedistance between the first and second joints. The universal reducer mayinclude a ball joint, a universal joint, a pivot, a slot, a collar, abearing, a dove-tail, a ball-joint, a gimbal, a level, or a sleeve thatpermits movement of the translatable transverse shafts in two or moredimensions. In another aspect, the universal reducer further may alsoinclude a fastener that semi-permanently fixes the position of thereducer in relation to the first, the second or both translatabletransverse shafts. The first and second joints may each include anindependent fastener that semi-permanently fixes the relative positionof the first spinal rod manipulator to the first translatable transverseshaft, the second spinal rod manipulator to the second translatabletransverse shaft or both the first and second spinal rod manipulator tothe first and second translatable transverse shafts, respectively.

The present invention also includes a kit that includes a rod linkreducer of a spinal fixation system, the rod link reducer having a firstand a second spinal rod manipulator; a first spinal rod manipulatorjoint connected to the first spinal rod manipulator and a second spinalrod manipulator joint connected to the second spinal rod manipulator; afirst and a second translatable transverse shaft connected to the firstand second joints, respectively; and a universal reducer connected toboth the first and second translatable transverse shafts, wherein thereducer, the shafts and the linkers provide movement and temporaryfixation of a spine that has been manipulated into a final positionduring spinal surgery. The kit may also include two or more pediclescrew into two or more vertebra, the pedicle screw including a bonefastener and a rod coupling head, the rod coupling head comprisingseparate lower and upper lower rod couplings: the lower rod couplingincluding: a lateral rod opening adapted to receive a permanent rod; anangled bore extends into the lateral rod opening; and a permanent rodfastener in the angled bore to engage a permanent rod in the lateral rodopening; and a upper rod coupling including: an upper rod openingadapted to receive a temporary rod, wherein the upper rod opening isformed to receive a temporary rod fastener; and two or more temporaryrod fasteners. The kit may also include at least one of two or morepermanent rods, two or more temporary rods, one or more rod linkreducers, a plurality of pedicle screws and one or more leveragehandles.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures and in which:

FIG. 1 shows one embodiment of the pedicle screw of the presentinvention.

FIGS. 2A to 2C show a cross-sectional view of the pedicle screw inoperation.

FIGS. 3A and 3B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10.

FIGS. 4A and 4B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10.

FIGS. 5A and 5B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10.

FIGS. 6A and 6B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10.

FIGS. 7A and 7B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10.

FIG. 8 shows a rod link reducer 10 for use with the present invention.

FIG. 9 is a cross-sectional side view of one embodiment of the rod linkreducer 10 present invention.

FIG. 10 is a side view of one embodiment of a rod manipulator.

FIGS. 11 to 13 show the first step in a spinal fixation process.

FIG. 14 shows the use of the rod link reducer and pedicle screw of thepresent invention.

FIG. 15 shows an overlay of the planning and tools for a surgicalprocedure to correct a severe spinal deformity.

FIGS. 16A to 16E shows the invention in use a procedure that includesdistraction, translation and apical derotation for correction of asingle severe spinal curve.

FIGS. 17A to 17E shows the invention in use a procedure for correctionof a double major severe spinal curve (Thoracic and Lumbar curve).

FIG. 18 is a detailed view of one embodiment of an apical derotationwithout linking the two pedicle screws.

FIG. 19 is an isometric view of a design of the rod-link reducer of thepresent invention.

FIG. 20 is an isometric view rod-link reducer of the present invention.

FIG. 21 is an isometric view of another design of the rod-link reducerof the present invention.

FIG. 22 shows a six-segment plastic spine model was instrumented to testthree constructs: (1) temporary rod/apical rod-link reducer (leftpanel); (2) provisional rod (center panel); and (3) final rod (rightpanel).

FIG. 23 is a picture that illustrates a perspective view of a rod-linkreduce which links and locks the provisional rods on the concavity

FIG. 24 is a picture that illustrates a perspective view of a rod-linkreduce which links and locks the provisional rods on the convexity

FIGS. 25-26 are pictures illustrating perspective view of the parts ofthe rod-link reducer.

FIG. 27 is a picture that illustrates a cross sectional view of therod-link reducer on the coronal plane.

FIG. 28 is a picture that illustrates a cross sectional view of therod-link reducer on the sagittal plane.

FIG. 29 is an image that shows the pedicle screws, provisional rods, andtwo rod-link-reducers are fixed in a coronal curve deformity model.

FIG. 30 is an image that shows the rod-link-reducers correct the coronalcurve.

FIG. 31 is an image that shows the provisional rods and therod-link-reducers and the final rods are with the spine which iscorrected.

FIG. 32 is an image that shows the final rods with the spine which iscorrected.

FIG. 33 is an image that shows the rod-link-reducers correct thesagittal curve to the normal kyphosis.

FIG. 34 is an image that shows the rod-link-reducers correct thesagittal curve to the normal lordosis.

FIG. 35 is an image that shows the pedicle screws, provisional rods, andtwo rod-link-reducers are fixed in a sagittal curve deformity model.

FIG. 36 is an image that shows the final rod insertion after thesagittal curve correction.

FIG. 37 is an image that shows the final rods are with the spine whichis corrected.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts thatcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention.

To facilitate the understanding of this invention, a number of terms aredefined below. Terms defined herein have meanings as commonly understoodby a person of ordinary skill in the areas relevant to the presentinvention. Terms such as “a”, “an” and “the” are not intended to referto only a singular entity, but include the general class of which aspecific example may be used for illustration. The terminology herein isused to describe specific embodiments of the invention, but their usagedoes not delimit the invention, except as outlined in the claims.

Posterior vertebral column resection (PVCR) can be used for correctionof the most severe spinal deformities. Current implant strategies usedfor more common and moderate spinal deformity are not ideal for thosecomplex cases. Sure they do not provide continuous stability of thespine as one transition between resection and correction, arecumbersome, and the application of correction forces are not ideal. Thenew system disclosed herein was designed specifically to surgicallytreat severe spinal deformity.

The treatment of severe rigid spinal deformity is a demanding anddifficult surgical challenge. The PVCR has been considered to be aneffective alternative to the conventional anteriorposterior VCR insevere rigid spinal deformity. However, the current implant strategiesused during PVCR afford the limited correction, potential risk of spinalcord injuries, and long operative time. This new instrumentation systemmay offer: 1) better maintenance of spinal stability throughout thesurgical procedure to reduce risk of the spinal cord injuries; 2) morereliable reconstruction of the vertebral column; 3) better and easiercorrection of the deformity; and 4) shorter operative time.

The novel pedicle screw/rod-link reducer posterior instrumentationsystem was developed to provide a safer, easier and improved deformitycorrection, as well as shorter surgical time for the PVCR of the severespinal deformity. Biomechanical evaluation of this system demonstratedspinal stability throughout the surgical procedure to reduce the risk ofspinal cord injuries.

The temporary rod/rod-link reducer construct provided similar stiffnessand stability compared to the provisional and final rod constructs. Thisnew system may offer a safer, easier and improved deformity correction,as well as shorter surgical time for the PVCR of the severe spinaldeformity.

Significance: Current implant strategies used for more common andmoderate spinal deformity are not ideal for the most severe spinaldeformities. A novel pedicle screw/rod-link reducer has been designed tooffer better maintenance of spinal stability throughout the surgicalprocedure to reduce risk of the spinal cord injuries. This system maytherefore provide a safer, easier and improved deformity correction, aswell as shorter surgical time for the PVCR of the severe spinaldeformity.

Implant Components: The instrumentation system may include one or moreof the following components: a pedicle screw, a rod-link reducer,reduction handle, temporary long rod, and final rod. The pedicle screwincludes a threaded shank for insertion into the bone and a screw headhaving a first aperture and a second aperture. The first aperture has abasic “U” (tulip) shape (top-loading component) that extends from thetop of the screw head and is open on both sides of the screw head toreceive a first longitudinal member (a temporary rod) and a set offemale threads formed in the inner walls of the first aperture. A firstcompression member engages the set of female threads of the firstaperture and the face of the first compression member contacts the firstlongitudinal member. The second aperture has a basic “C” shape(side-loading component) that lines up superior to the threaded shankand inferior to the first aperture. The second aperture is open on bothsides of the head to receive a second longitudinal member (a final rod).The second aperture also includes a second set of female threads thataccommodate a second compression member that screwably engages thesecond set of female threads and the face of the second compressionmember contacts the second longitudinal member. There is a breakawaymechanism between the first and second apertures.

The rod-link reducer has a basic “H” shape that rigidly links and locksthe first longitudinal members (temporary rods). The rod-link reducerincludes: 1) two top-tightening locking mechanisms (break-off setscrews) those provide access ensure the adequate grip on the temporaryrods by the set screws; 2) an adjustable central mechanism byfunctioning in a multi-axial manner, allows attachment to the rod at anyorientation in the coronal, sagittal, and transverse planes. Themechanism allows to make compression, distraction, derotation andcantilever method; 3) two adjustable lateral mechanisms (break-off setscrews) allow the locking mechanisms adequately to attach the temporaryrods; 4) two squared ends those connect with two reduction handles.

The reduction handle is a column shape and has two portion ends. Thefirst end has a squared access that connects with the squared end of therod-link reducer. The second end is a solid column. The temporary rodand the final rod are the diameter of 5.5 mm rods those are made ofstainless steel or titanium.

In operation, the present invention may be used as follows: With thespine exposed posteriorly, the pedicle screws will be insertedsegmentally, except for the resected levels (apex). The spine is thendivided into cephalad and caudal portions by the resected levels. At thecephalad portion, two temporary rods will be fixed on the convex andconcave side via the first aperture of the pedicle screw respectively.Another two temporary rods will be similarly fixed at the caudalportion. The two temporary rods on the concave side will be connectedwith a rod-link reducer and locked to the shape of the deformity withoutany attempt at correction. Resection of the vertebral column will beperformed at the convex side of the apex. Following resection on theconvex side, another rod-link reducer will be connected and locked onthe two convex temporary rods. The resection of the remaining vertebrawill be performed on the concave side.

Deformity correction is performed by loosening the adjustable centralmechanism of the rod-link reducer on the convex side with the reductionhandles, which will be gradually compressed to shorten the resected gap.During the compression the resected gap on the convexity, the centralpart of rod-link reducer on the concavity will be gradually loosen tomatch the compression/shortening on the convexity.

After deformity correction, two final rods will be fixed on the convexand concave side via the second aperture of the pedicle screwrespectively. The two rod-link reducers will be unlocked and alltemporary rods will be removal. A custom wrench will be used to removethe first aperture parts of the pedicle screw.

The pedicle screw and any of its components including the bone fastener,threads, neck and screwhead, may be made of a non-organic material thatis durable and that can be implanted in a human body, such as titanium,stainless steel, spring steel, aluminum, Niobium, carbon fiber,ceramics, polymers, composites or any relatively hard material (e.g.Titanium-Aluminium-Niobium-alloy). Generally, the material selected willbe biocompatible, that is, compatible with the surrounding bone andtissue.

The present invention provides a substantial improvement in addressingclinical problems indicated for surgical treatment of chronic or acutespinal injuries, including traumatic spinal injuries, scoliosis(abnormal lateral curvature of the spine), kyphosis (abnormal forwardcurvature of the spine, often in the thoracic spine), excess lordosis(abnormal backward curvature of the spine, often in the lumbar spine),spondylolisthesis (forward displacement of one vertebra over another,often in a lumbar or cervical spine) and other disorders caused byabnormalities, disease or trauma, such as ruptured or slipped discs,degenerative disc disease, fractured vertebra, and the like.

FIG. 1 shows one embodiment of the pedicle screw 10 of the presentinvention. The pedicle screw 10 includes a bone fastener 12 and a rodcoupling head 14. The rod coupling head 14 includes a lower rod coupling16 having a lower rod opening 18, depicted in a lateral configuration.The lower rod opening 18 may have any angle so long as the material ofthe pedicle screw 10 that surrounds the lower rod opening 18 issufficiently strong to retain and affix a permanent rod. The lower rodcoupling 16 also includes a bore 20, through which a permanent rodfastener 22 can be inserted to fasten a permanent rod. As in the case ofthe lower rod opening 18, the material of the pedicle screw 10surrounding the bore 20 will also be sufficiently strong to retain andaffix a permanent rod. The upper rod coupling 24 has an upper rodopening 25. The upper rod coupling 24 is formed to permit the user toinsert a temporary rod using a temporary rod fastener 28. The lower andupper rod couplings 16 and 24, respectively will often be may be made ofunitary construction. For illustration purposes, and not necessarily asan element or limitation, a transition 32 is denoted. In unitaryembodiments, the transition 32 may be modified (e.g., notched, cut,scratched or weakened) to provide for the breakage of the upper rodcoupling 24. In another embodiment, the transition 32 may provide asemi-permanent attachment between the lower rod coupling 16 and theupper rod coupling 24, such that the transition is a universal joint, apivot, a slot, a collar, a bearing, a dove-tail, a ball-joint, a gimbal,a level, or a sleeve. Likewise, the lower rod coupling 16 and the bonefastener may be connected with a universal joint, a pivot, a slot, acollar, a bearing, a dove-tail, a ball-joint, a gimbal, a level, or asleeve. When made in a unitary construction, the pedicle screw 10 may bemachined, sintered, cast, welded or glued as long as the pedicle screwis of sufficient strength for the bone fixation application.

FIGS. 2A to 2C show a cross-sectional view of the pedicle screw 10 inoperation. In FIG. 2A, the pedicle screw has been affixed to a bone (notdepicted) and a temporary rod 34 has been inserted into the upper rodopening 26 and semi-permanently affixed using the temporary rod fastener28. In the embodiment depicted, the upper rod opening 26 is showsinternally threaded and the temporary rod fastener 28 is showsexternally threaded. The skilled artisan will recognize that the presentinvention also includes fastener embodiments in which the threading isreversed, the threading is external to the upper rod coupling and thefastener is internally threaded, the fastener is a cap, the fastener andthe coupling snap together, are wedged together, twist and lock.Likewise, the permanent rod fastener is also able to engage thepermanent rod in a variety of manners, including pins, latches,threading, snapping, wedging and locking. The permanent rod may even beglued or welded.

FIG. 2B shows the addition of the permanent rod 36 in addition to thetemporary rod 34. Next, the temporary rod fastener 28 and the temporaryrod are removed (not depicted). Finally, FIG. 2C shows the finalassembly in which the upper rod coupling is removed completely bybreaking the upper rod coupling into tabs 40 at breakpoints 38.

FIGS. 3A and 3B shows an isometric view and a cross-sectional view,respectively, of the pedicle screw 10 in which the lower rod coupling 16and the upper rod coupling 24 are connected by in which a screw portion50 is fastened into opening 52 and which permits the potential for somerotations about the axis of the screw portion 50. After the permanentrod has been affixed into the pedicle screw 10, the upper rod fastener24 is removed.

FIGS. 3A and 3B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10 in which the lower rod coupling 16and the upper rod coupling 24 are connected by in which a screw portion50 is fastened into opening 52 and which permits the potential for somerotations about the axis of the screw portion 50. After the permanentrod has been affixed into the pedicle screw 10, the upper rod fastener24 is removed.

FIGS. 4A and 4B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10 in which the lower rod coupling 16and the upper rod coupling 24 are connected by in which a screw 54 isfastened through opening 56 into opening 52 and which permits thepotential for some rotations about the axis of the screw 54. After thepermanent rod has been affixed into the pedicle screw 10, the upper rodfastener 24 is removed by unscrewing screw 54. The screw 54 also permitscontrol over the mechanical force required to rotate the upper rodcoupling 24. For configurations in which the lower rod coupling 16 andthe upper rod coupling 24 are separate, the interface between the twomake be smooth, rough or patterned (e.g., random or non-random) orcoated.

FIGS. 5A and 5B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10 in which the lower rod coupling 16and the upper rod coupling 24 are connected by in which a screw 54 isfastened through opening 56 into opening 52 and which permits thepotential for some rotations about the axis of the screw 54. After thepermanent rod has been affixed into the pedicle screw 10, the upper rodfastener 24 is removed by unscrewing screw 54. In this configuration thelower rod coupling 16 and the upper rod coupling 24 are separate and theinterface between the upper and lower rod couplings (24, 16) is enhancedby the addition of a slit 60 that dove-tails with a notch 62. The notch62 can even be placed at an angle or can also be made square such thatthe upper rod coupling 24 can be placed parallel or perpendicular to thedirection of the permanent or temporary rods.

FIGS. 6A and 6B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10 in which the lower rod coupling 16and the upper rod coupling 24 are connected by in which a screw 54 isfastened through opening 56 into opening 52 and which permits thepotential for some rotations about the axis of the screw 54. After thepermanent rod has been affixed into the pedicle screw 10, the upper rodfastener 24 is removed by unscrewing screw 54. In this configuration thelower rod coupling 16 and the upper rod coupling 24 are separate and theinterface between the upper and lower rod couplings (24, 16) is enhancedby the addition of a slit 60 that dove-tails with an external notch 62.The notch 62 can even be placed at an angle or can also be made squaresuch that the upper rod coupling 24 can be placed parallel orperpendicular to the direction of the permanent or temporary rods.

FIGS. 7A and 7B show an isometric view and a cross-sectional view,respectively, of the pedicle screw 10 in which the lower rod coupling 16and the upper rod coupling 24 are connected by in which a screw 54 isfastened through opening 56 into opening 52 and which permits thepotential for some rotations about the axis of the screw 54. After thepermanent rod has been affixed into the pedicle screw 10, the upper rodfastener 24 is removed by unscrewing screw 54. In this configuration thelower rod coupling 16 and the upper rod coupling 24 are separate and theinterface between the upper and lower rod couplings (24, 16) is enhancedby the addition of dove-tail joints (shown in two differentconfigurations). The notch 62 can even be placed at an angle or can alsobe made square such that the upper rod coupling 24 can be placedparallel or perpendicular to the direction of the permanent or temporaryrods.

FIG. 8 is an isometric view of a rod link reducer 100 for use with thepresent invention. The rod link reducer 100 includes first and secondspinal rod manipulators 102, 104, which are connected to a first spinalrod manipulator joint 106 connected to the first spinal rod manipulator102 and a second spinal rod manipulator joint 108 connected to thesecond spinal rod manipulator 104. First and second translatabletransverse shafts 110, 112 connected to the first and second joints 106,108, respectively, which connected to a reducer 114 connected to boththe first and second translatable transverse shafts 110, 112, whereinthe reducer 114, the shafts 110, 112 and the linkers 106, 108 providemovement and temporary fixation of a spine that has been manipulatedinto a final position during spinal surgery.

FIG. 9 is a cross-sectional side view of one embodiment of the rod linkreducer 10 present invention, shown in this embodiment with screws 116.The skilled artisan will recognize that the screws 16 provide reversiblemechanical fixation between the different parts of the system that canbe tightened and loosened during spinal adjustments. Any given joint mayinclude some friction or resistance during use up to and including totalfixation. The screws 116 can be replaced or include pins, set screws,cotter pins, internal or external compression, compression fittings,collared fittings, screw-drives or even electrical, pneumatic orhydraulic movement or pressure. In the embodiment depicted, first andsecond translatable transverse shafts 110, 112 as shown as adjustmentsleeves slidably fitted within a housing 118 is an axial bore 120 andwithin the axial bore a strut 122 in which the screw 116 serves as afastener positioned to secure the strut 122 within the housing 118,wherein the struts 112 allow for coarse longitudinal movement of thestrut 122 with respect to the strut housing 118. The skilled artisanwill recognize that the strut-bore configuration can be reversed(bore-strut) or replaced with side-by-side struts, internal-externalslidable pins within a groove, screw-drives, magnetic drives,electrical, pneumatic or hydraulic drives so long as the translatabletransverse shafts 110, 112 permit the user to expand and/or contract oneor both the translatable transverse shafts 110, 112.

FIG. 10 is a side view of one embodiment of rod manipulators 102, 104.In this side view screws 116 are shown as well as either first or secondjoint 106, 108. The rod manipulators 102, 104 include a head 130 thathas an opening 132 that first a rod (temporary or permanent) for spinalfixation. The screw 116 is used to engage and retain the rod. The rodmanipulators 102, 104 will be made from a material with sufficienttensile strength to allow the manipulator to fasten to the rod but alsoto permit the user to translate movement from the handle 134 into therod in any direction. The handle 134 may itself also include a coating(not depicted) to improve the grip of a user during use or may be shapedto permit a second handle to attach to the handle 134 to increase theleverage of a user when manipulating a spine during spinal fixationsurgery. Again, while this embodiment is shown with screws, anyfastening method (pins, set-screws, compression, collets, etc.) may beused to fasten the various components of the rod link reducer of thepresent invention.

The rod link reducer 100 may be used in conjunction with existing spinalscrew and rod fixation systems or may be used in conjunction with thepedicle screw 10. The size and thickness of rods may be varied dependingon the type of surgery, tensile strength required and preference of theuser.

FIG. 11 shows the first step in a spinal fixation process. In thisembodiment, a temporary rod 34 has been attached to pedicle screws 10(while not depicted, the pedicle screws may be attached individualvertebra. Examples of conditions that may be treated using the presentinvention include kyphosis, lordosis, scoliosis or combinations thereof.A rod link reducer 100 is shown connected to the temporary rod 34 andthe spine (not shown) has been aligned. In FIG. 12, the permanent rod 36is introduced into the pedicle screw 10 while the rod link reducer 110holds the entire assembly in place while the permanent rod ispermanently affixed to the pedicle screws 10. Finally, FIG. 13 shows thefinal spinal rod assembly after removing the temporary rod and thebreakable tabs from the pedicle screws 10.

FIG. 14 shows the advantage provided by the rod link reducer 100 of thepresent invention. In this top view of the operation of the presentinvention, two rod link reducers 100 a, 100 b are connected to two pairsof temporary rods 34 a-d and pedicle screws 10 a-h. By compressing,distracting or rotating the rod link reducers 100 a, 100 b, the user canmanipulate the spine in all directions necessary for spinal alignmentand fixation. Furthermore, the user is able to compress, distract, andtranslate any of the spinal segments until arriving at a final position.The rod link reducer 100 is tightened upon final positioning and thepermanent rod can be inserted into the pedicle screws. Furthermore, therod link reducers 100 a, 100 b can be tightened in a single plane at atime while still manipulating the rest of the spine in the other planes.

The present invention can be used to correct mild to severe spinaldeformities, including sever deformities. The present invention includesthe following advantages: a reduced risk of intraoperative mishaps dueto the instability caused by exchanging the temporary rods with thepermanent rod, it increases the directions in which the deformities canbe corrected and reduces the number of tools, and surgical time causedby temporary rod failure or slipping that occurs between the finalpositioning of the temporary rods and the fixation of the permanent rod.It has been found that the present invention allows the surgeon toshorten the duration of the operation and also increases the extent ofcorrection in a single procedure.

FIG. 15 shows an overlay of the planning and tools for a surgicalprocedure to correct a severe spinal deformity. An x-ray is shown of amalformed spine and the tools are overlaid to plan the positioning ofthe pedicle screws, rods and rod link reducer. Next, the user determinesthe various different steps in the correction, including thecompression, distraction, apical derotation and translation of one orboth pairs of temporary rods. Also shown are optional tools or handlesto increase the leverage of the surgeon, taking into account theaccessibility of tools due to the translation and rotation of theunderlying spine prior to treatment. In certain cases, the steps may bealternated to maximize the leverage of the rod link reducers indifferent direction, thereby maximizing efficiency of the movement,increasing the effectiveness of the procedure and minimizing the time ofthe procedure.

FIGS. 16A to 16E shows the invention in use a procedure that includesdistraction, translation and apical derotation. FIG. 16A shows a singleright thoracic rigid curve 200. FIG. 16B shows the first step in theprocedure in which temporary rods 34 a and 34 b, which are fixed at aproximal portion of the spine and another one fixed at distal portion ofthe curve about a concavity. The temporary rods 34 a, 34 b are attachedto the single right thoracic rigid curve 200 using pedicle screws (notdepicted) on either end of the site for distraction, translation andapical derotation. One example of the pedicle screws that may be used inthe procedure is pedicle screw 10. FIG. 16C shows the rod link reducer100 connected to temporary rods 34 a and 34 b on the concavity. Next,derotation instruments 202 a-c are attached to the apical vertebrae.FIG. 16D shows the combined distraction, translation and apicalderotation of the spine in which the rod link reducer 100 is used forthe distraction and translation (arrows) and the derotation instruments202 a-c, seen as a cross-sectional view of the spine at a vertebrae 304,is are used alone or in combination (in this instance) for apicalderotation via linker 308 attached to pedicle screws 310. The skilledartisan will recognize that these tools may be used for a distraction,translation and/or apical rotation, however, most procedures willinvolve a combinations of these manipulations. FIG. 16E shows avariation of the combined distraction, translation and apical derotationoutlined in FIGS. 16A-16D in which pairs of temporary rods 34 a, 34 bare shown in parallel along the proximal and distal segments of thespine. A second rod link reducer 101 is shown as two provisional rods 34are on the concavity. Convex provisional compression is to help thecurve correction.

FIGS. 17A to 17E shows the use of the rod link reducer 100 on a spinalconvexity. FIG. 17A shows a double major rigid curve 300 onto which twotemporary rods 34 a, 34 b are on the concavity of the thoracic curve andtwo temporary rods 34 c, 34 d are on the concavity of the lumbar curve.FIG. 17C shows the attachment of two rod-link reducers 100, 100 fixed onthe concavity for both curves, respectively. Next, the combineddistraction, translation and apical derotation for both curves isdepicted in which derotation instruments 202 a-c and 202 d-e areattached to the vertebrae 304, 305 through pedicle screws 306 vialinkers 308. The linker 308 serve as attachment points for thederotation instruments 202 a-e and can be used to increase the leveragefor the distraction, translation and apical derotation. FIG. 17E showsthe positioning of a pair of convex temporary rods at each site are usedfor compression maneuvers to help in the correction of the two curvesusing two rod link reducer 100, 101 about each of the treatment sites.

FIG. 18 is a detailed view of one embodiment of an apical derotationwithout linking the two pedicle screws 310 a,b. In this embodiment, thelinkers 308 a,b are used directly to aid in the apical rotation of asingle vertebrae 304 without a linked derotation instrument.

FIGS. 19, 20 and 21 shows various designs of the rod-link reducer 100.FIG. 19 shows a rod link reducer 100 that includes a universal connectoron the central portion. The rod link reducer 100 includes first andsecond spinal rod manipulators 102, 104, which are connected to a firstspinal rod manipulator joint 106 connected to the first spinal rodmanipulator 102 and a second spinal rod manipulator joint 108 connectedto the second spinal rod manipulator 104. First and second translatabletransverse shafts 110, 112 slides through joints 106, 108, respectively.The joints 106, 108 can tighten to fix the transverse shafts 110, 112individually. In FIG. 19, the two translatable transverse shafts 110,112 have movement around a reducer 114, which is depicted as a singlereducer with universal movement. In one example, the reducer 114 may befixed to act as a straight rod to limit the movement of the first andsecond spinal rod manipulators 102, 104 in two planes. FIGS. 20 and 21show the rotation between the rod-connector. This design would bestronger and easily to install and give surgeons more free for surgery.

As the skilled artisan will appreciate the first and second translatabletransverse shafts 110, 112 may be in-line, as depicted in FIGS. 19-21,or may be parallel on two separate planes allowing the first and secondtranslatable transverse shafts to extend past the ends of the oppositeshaft. By allowing the first and second translatable transverse shaftsto move in parallel, the distance between first and second spinal rodmanipulators 102, 104 can be reduced to a minimum in certainmanipulations. As can also be seen from these figures, the first andsecond rod manipulator joints 106, 108 can slide toward or away from thetemporary rods 34 a,b. The configuration presented herein allows sixdegrees of freedom in any direction, while also providing the necessarystrength and leverage to perform complex spinal deformity surgery in areduced space.

FIG. 22A to 22D shows the new pedicle screw and apical rod-link reducerposterior instrumentation system that includes: (1) pedicle screw with ascrew head that can receive two 5.5-mm rods (provisional and final rods)with a breakaway mechanism between the two rod-receivers; (2) a rod-linkreducer rigidly linking the provisional rods at the apex, allowingattachment to the rod at any orientation so as to easily makecompression, distraction, derotation and cantilever maneuver. While thedeformity is corrected using the provisional rod/rod-link reducer, thefinal rod is fixed and then the provisional ones are removed. Asix-segment plastic spine model was instrumented to model threeconstructs: (1) provisional rod/apical rod-link reducer; (2) provisionalrod; and (3) final rod. The spines were tested using pure bendingmoments. Segmental range of motion (ROM) was recorded using athree-dimensional motion analysis system.

FIG. 23 is a drawing illustrating a perspective view of the rod-linkreducer 100 which links and locks the first and second translatabletransverse shafts 110/112. The reducer 114 provides a mechanism torotate the device on the concavity. For example, the reducer 114 canhave a ball bearing like mechanism controlled by the screw 116 as seenin FIG. 23. FIG. 24 is a drawing illustrating a perspective view of therod-link reducer 100 which links and locks the first and secondtranslatable transverse shafts 110/112. The reducer 114 provides amechanism to rotate the device on the convexity.

FIGS. 25 and 26 are diagrams illustrating perspective views of the partsof the rod-link reducer 100. Specifically, FIG. 25 shows the first andsecond translatable transverse shafts 110/112, and the reducer 114 andthe screw 116. FIG. 26 shows the parts of the either first or secondjoint 106/108.

FIG. 27 is a diagram showing the combination of parts from FIGS. 25 and26 with the first and second translatable transverse shafts 110/112,reducer 114, the screw 116, and either first or second joint 106/108.

FIG. 28 is a diagram similar to FIG. 10 with a side view of oneembodiment of rod manipulators 102/104. In this side view screws 116 areshown as well as either first or second joint 106/108. The rodmanipulators 102/104 include a head 130 that has an opening 132 thatfirst a rod (temporary or permanent) for spinal fixation. The screw 116is used to engage and retain the rod. In particular, the cross sectionsof the either first or second joint 106/108 are shown.

FIG. 29 is an image of 2 rod-link reducers 100 a/b which links and locksthe first and second translatable transverse shafts 110 a/b and 112 a/b.The reducer 114 a/b provides a mechanism to rotate the device on theconcavity. For example, the reducer 114 can have a ball bearing likemechanism controlled by the screw 116 a/b. The rod link reducer 100 a/bincludes first and second spinal rod manipulators 102 a/b and 104 a/b,which are connected to a first spinal rod manipulator joint 106 a/bconnected to the first spinal rod manipulator 102 a/b and a secondspinal rod manipulator joint 108 a/b connected to the second spinal rodmanipulator 104 a/b. First and second translatable transverse shafts 110a/b, 112 a/b slides through joints 106 a/b, 108 a/b, respectively. Thejoints 106 a/b and 108 a/b can tighten to fix the transverse shafts 110a/b and 112 a/b individually. The two translatable transverse shafts 110a/b, 112 a/b have movement around the reducer 114 a/b, which is depictedas a single reducer with universal movement. The first and second spinalrod manipulators 102 a/b and 104 a/b are connected to the temporary rods34 a/b/c/d affixed to the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l inthe spine for alignment.

FIG. 30 is an image of 2 rod-link reducer 100 a/b which links and locksthe first and second translatable transverse shafts 110 a/b and 112 a/bshowing the reducers correcting the coronal curve. The reducer 114 a/bprovides a mechanism to rotate the device on the concavity. For example,the reducer 114 can have a ball bearing like mechanism controlled by thescrew 116 a/b. The rod link reducer 100 a/b includes first and secondspinal rod manipulators 102 a/b and 104 a/b, which are connected to afirst spinal rod manipulator joint 106 a/b connected to the first spinalrod manipulator 102 a/b and a second spinal rod manipulator joint 108a/b connected to the second spinal rod manipulator 104 a/b. First andsecond translatable transverse shafts 110 a/b, 112 a/b slides throughjoints 106 a/b, 108 a/b, respectively. The joints 106 a/b and 108 a/bcan tighten to fix the transverse shafts 110 a/b and 112 a/bindividually. The two translatable transverse shafts 110 a/b, 112 a/bhave movement around the reducer 114 a/b, which is depicted as a singlereducer with universal movement. The first and second spinal rodmanipulators 102 a/b and 104 a/b are connected to the temporary rods 34a/b/c/d affixed to the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l in thespine for alignment.

FIG. 31 is an image that shows the rod-link-reducers and the provisionalrods and the final rods with the spine which is corrected. The reducer114 a/b provides a mechanism to rotate the device on the concavity. Forexample, the reducer 114 can have a ball bearing like mechanismcontrolled by the screw 116 a/b. The rod link reducer 100 a/b includesfirst and second spinal rod manipulators 102 a/b and 104 a/b, which areconnected to a first spinal rod manipulator joint 106 a/b connected tothe first spinal rod manipulator 102 a/b and a second spinal rodmanipulator joint 108 a/b connected to the second spinal rod manipulator104 a/b. First and second translatable transverse shafts 110 a/b, 112a/b slides through joints 106 a/b, 108 a/b, respectively. The joints 106a/b and 108 a/b can tighten to fix the transverse shafts 110 a/b and 112a/b individually. The two translatable transverse shafts 110 a/b, 112a/b have movement around the reducer 114 a/b, which is depicted as asingle reducer with universal movement. The first and second spinal rodmanipulators 102 a/b and 104 a/b are connected to the temporary rods 34a/b/c/d affixed to the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l in thespine for alignment. In addition to the temporary rods 34 a/b/c/d,permanent rods 36 a/b are introduced into the pedicle screws 10a/b/c/d/e/f/g/h/i/j/k/l while the rod link reducers 100 a/b holds theentire assembly in place. FIG. 31 shows the permanent rods 36 a/b withthe temporary rods 34 a/b/c/ and the rod link reducers 100 a/b inposition.

FIG. 32 is an image that shows the final rods with the spine which iscorrected. FIG. 32, the permanent rods 36 a/b are introduced into thepedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l while the rod link reducer(not shown) holds the entire assembly in place while the permanent rods36 a/b are permanently affixed to the pedicle screws 10a/b/c/d/e/f/g/h/i/j/k/l. FIG. 32 shows the final spinal rod assemblyafter removing the temporary rods (not shown) and the breakable tabsfrom the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l.

FIG. 33 is an image that shows the rod-link-reducers correct thesagittal curve to the normal kyphosis. The reducer 114 a/b provides amechanism to rotate the device. For example, the reducer 114 can have aball bearing like mechanism controlled by the screw 116 a/b. The rodlink reducer 100 a/b includes first and second spinal rod manipulators102 a/b and 104 a/b, which are connected to a first spinal rodmanipulator joint 106 a/b connected to the first spinal rod manipulator102 a/b and a second spinal rod manipulator joint 108 a/b connected tothe second spinal rod manipulator 104 a/b. First and second translatabletransverse shafts 110 a/b, 112 a/b slides through joints 106 a/b, 108a/b, respectively. The joints 106 a/b and 108 a/b can tighten to fix thetransverse shafts 110 a/b and 112 a/b individually. The two translatabletransverse shafts 110 a/b, 112 a/b have movement around the reducer 114a/b, which is depicted as a single reducer with universal movement. Thefirst and second spinal rod manipulators 102 a/b and 104 a/b areconnected to the temporary rods 34 a/b/c/d affixed to the pedicle screws10 a/b/c/d/e/f/g/h/i/j/k/l in the spine for alignment.

FIG. 34 is an image that shows the rod-link-reducers correct thesagittal curve to the normal lordosis. The reducer 114 a/b provides amechanism to rotate the device. For example, the reducer 114 can have aball bearing like mechanism controlled by the screw 116 a/b. The rodlink reducer 100 a/b includes first and second spinal rod manipulators102 a/b and 104 a/b, which are connected to a first spinal rodmanipulator joint 106 a/b connected to the first spinal rod manipulator102 a/b and a second spinal rod manipulator joint 108 a/b connected tothe second spinal rod manipulator 104 a/b. First and second translatabletransverse shafts 110 a/b, 112 a/b slides through joints 106 a/b, 108a/b, respectively. The joints 106 a/b and 108 a/b can tighten to fix thetransverse shafts 110 a/b and 112 a/b individually. The two translatabletransverse shafts 110 a/b, 112 a/b have movement around the reducer 114a/b, which is depicted as a single reducer with universal movement. Thefirst and second spinal rod manipulators 102 a/b and 104 a/b areconnected to the temporary rods 34 a/b/c/d affixed to the pedicle screws10 a/b/c/d/e/f/g/h/i/j/k/l in the spine for alignment. The skilledartisan will recognize that the instant invention may be used to correctall forms of alignments including kyphosis and lordosis.

FIG. 35 is an image that shows the pedicle screws, provisional rods, andtwo rod-link-reducers are fixed in a sagittal curve deformity model. Thereducer 114 a/b provides a mechanism to rotate the device. For example,the reducer 114 can have a ball bearing like mechanism controlled by thescrew 116 a/b. The rod link reducer 100 a/b includes first and secondspinal rod manipulators 102 a/b and 104 a/b, which are connected to afirst spinal rod manipulator joint 106 a/b connected to the first spinalrod manipulator 102 a/b and a second spinal rod manipulator joint 108a/b connected to the second spinal rod manipulator 104 a/b. First andsecond translatable transverse shafts 110 a/b, 112 a/b slides throughjoints 106 a/b, 108 a/b, respectively. The joints 106 a/b and 108 a/bcan tighten to fix the transverse shafts 110 a/b and 112 a/bindividually. The two translatable transverse shafts 110 a/b, 112 a/bhave movement around the reducer 114 a/b, which is depicted as a singlereducer with universal movement. The first and second spinal rodmanipulators 102 a/b and 104 a/b are connected to the temporary rods 34a/b/c/d affixed to the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l in thespine for alignment.

FIG. 36 is an image that shows the final rod insertion after thesagittal curve correction. FIG. 36 is an image that shows therod-link-reducers and the provisional rods and the final rods with thespine which is corrected. The reducer 114 a/b provides a mechanism torotate the device on the concavity. For example, the reducer 114 canhave a ball bearing like mechanism controlled by the screw 116 a/b. Therod link reducer 100 a/b includes first and second spinal rodmanipulators 102 a/b and 104 a/b, which are connected to a first spinalrod manipulator joint 106 a/b connected to the first spinal rodmanipulator 102 a/b and a second spinal rod manipulator joint 108 a/bconnected to the second spinal rod manipulator 104 a/b. First and secondtranslatable transverse shafts 110 a/b, 112 a/b slides through joints106 a/b, 108 a/b, respectively. The joints 106 a/b and 108 a/b cantighten to fix the transverse shafts 110 a/b and 112 a/b individually.The two translatable transverse shafts 110 a/b, 112 a/b have movementaround the reducer 114 a/b, which is depicted as a single reducer withuniversal movement. The first and second spinal rod manipulators 102 a/band 104 a/b are connected to the temporary rods 34 a/b/c/d affixed tothe pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l in the spine foralignment. In addition to the temporary rods 34 a/b/c/d, permanent rod36 are introduced into the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/lwhile the rod link reducers 100 a/b holds the entire assembly in place.FIG. 36 shows the permanent rod 36 with the temporary rods 34 a/b/c/dand the rod link reducers 100 a/b in position.

FIG. 37 is an image that shows the final rods are with the spine whichis corrected. FIG. 37, the permanent rod 36 are introduced into thepedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l while the rod link reducer(not shown) holds the entire assembly in place while the permanent rod36 are permanently affixed to the pedicle screws 10a/b/c/d/e/f/g/h/i/j/k/l. FIG. 37 shows the final spinal rod assemblyafter removing the temporary rods (not shown) and the breakable tabsfrom the pedicle screws 10 a/b/c/d/e/f/g/h/i/j/k/l.

It was found that using the present invention no significant differencesin the ROM between the three constructs except right lateral bending inwhich the provisional rod/rod-link and the provisional rod constructsROM were greater than the final rod construct (P=0.005) (Table 1).

TABLE 1 Range of Motion (Degree) in the Three Constructs ProvisionalRod + Provisional Final Rod Link Rod Rod Flexion 4.3 ± 1.7 3.1 ± 0.2 3.2± 0.5 Extension 1.3 ± 0.1 1.2 ± 0.3 1.8 ± 0.6 Left Lateral Bending 1.8 ±0.8 1.9 ± 1   2.1 ± 0.6 Right Lateral Bending* 2.2 ± 0.3 2.3 ± 0.5 1.6 ±0.1 *ANOVA P-Value = 0.005, Provisional Rod + Rod Link and ProvisionalRod Construct ROM > Final Rod Construct.

The provisional rod/rod-link reducer construct provided similarstiffness and stability compared to the provisional and final rodconstructs. This new system may offer a safer, easier and improveddeformity correction, as well as shorter surgical time for the PVCR ofthe severe spinal deformity.

The novel pedicle screw/rod-link reducer offers better maintenance ofspinal stability throughout the surgical procedure to reduce risk of thespinal cord injuries. This system may therefore provide a safer, easierand improved deformity correction, as well as shorter surgical time forthe PVCR of the severe spinal deformity.

The present invention overcomes the following disadvantages of existingsystems, namely, the limitation for the apical vertebral derotation andtranslation. Another disadvantage or existing systems is the difficultyfor concave rod derotation and/or translation which result in pediclescrew loosening with damage to the spinal cord. The present inventionovercomes both of these advantages by providing a stable, sturdyplatform for use of temporary and permanent rods using a single pediclescrew. The pedicle screw of the present invention maximizes thestructural-mechanical properties of each fixation point (the lowerversus the upper rod coupling) for each specific type of rod (permanentor temporary) while at the same time maximizing the efficiency of thesurgical procedure with less tools and equipment. Furthermore, surgeonsare already familiar with similar tools and fasteners and do not have tolearn new procedures, techniques or the use of new tools.

It is contemplated that any embodiment discussed in this specificationcan be implemented with respect to any method, kit, reagent, orcomposition of the invention, and vice versa. Furthermore, compositionsof the invention can be used to achieve methods of the invention.

It will be understood that particular embodiments described herein areshown by way of illustration and not as limitations of the invention.The principal features of this invention can be employed in variousembodiments without departing from the scope of the invention. Thoseskilled in the art will recognize, or be able to ascertain using no morethan routine experimentation, numerous equivalents to the specificprocedures described herein. Such equivalents are considered to bewithin the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specificationare indicative of the level of skill of those skilled in the art towhich this invention pertains. All publications and patent applicationsare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.” The use of the term “or” in the claims isused to mean “and/or” unless explicitly indicated to refer toalternatives only or the alternatives are mutually exclusive, althoughthe disclosure supports a definition that refers to only alternativesand “and/or.” Throughout this application, the term “about” is used toindicate that a value includes the inherent variation of error for thedevice, the method being employed to determine the value, or thevariation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (andany form of comprising, such as “comprise” and “comprises”), “having”(and any form of having, such as “have” and “has”), “including” (and anyform of including, such as “includes” and “include”) or “containing”(and any form of containing, such as “contains” and “contain”) areinclusive or open-ended and do not exclude additional, unrecitedelements or method steps.

The term “or combinations thereof” as used herein refers to allpermutations and combinations of the listed items preceding the term.For example, “A, B, C, or combinations thereof” is intended to includeat least one of: A, B, C, AB, AC, BC, or ABC, and if order is importantin a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.Continuing with this example, expressly included are combinations thatcontain repeats of one or more item or term, such as BB, AAA, MB, BBC,AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan willunderstand that typically there is no limit on the number of items orterms in any combination, unless otherwise apparent from the context.

All of the compositions and/or methods disclosed and claimed herein canbe made and executed without undue experimentation in light of thepresent disclosure. While the compositions and methods of this inventionhave been described in terms of preferred embodiments, it will beapparent to those of skill in the art that variations may be applied tothe compositions and/or methods and in the steps or in the sequence ofsteps of the method described herein without departing from the concept,spirit and scope of the invention. All such similar substitutes andmodifications apparent to those skilled in the art are deemed to bewithin the spirit, scope and concept of the invention as defined by theappended claims.

REFERENCES

-   1. Maclennan A. Scoliosis. Br Med J 1922; 2: 865-6.-   2. Compere E L. Excision of hemivertebrae for correction of    congenital scoliois: report of two cases. JBJS 1932; 14-A; 555-62.-   3. Deviten V, Berven S, Smith J A, et al. Excision of hemivertebrae    in the management of congenital scoliosis involving the thoracic and    thoracolumbar spine. JBJS 2001; 83-B; 496-500.-   4. Floman Y, Penny J N, Micheli L J, et al. Osteotomy of the fusion    mass in scoliosis. JBJS 1982; 64-A: 1307-16.-   5. Luque E R. Vertebral column transposition. Orthop Trans 1983; 7:    29.-   6. Leatherman k D, Dickson R A. Two-stage corrective surgery for    congenital deformities of the spine. JBJS 1979; 61-B: 324-8.-   7. Tokunaga M, Minami S, Kitahara H, et al. Verteral decancellation    for severe scoliosis. Spine 2000; 25: 469-74.-   8. Wiles P. Resection of dorsalvertebrae in congenital scoliosis.    JBJS 1951, 33-A: 151-4.-   9. Bradford D S. Vertebral column resection. Orthop Tans 1987; 11:    502.-   10. Bradford D S and Boachie-Adjei O. One-stage anterior and    posterior hemivertebral resection and arthrodesis for congenital    scoliosis. JBJS 1990; 72-A: 536-40.-   11. Suk S, Kim J H, Kim W J, et al. Posterior vertebral column    resection for severe spinal deformities. Spine 2002; 27 (21):    2374-82.-   12. Suk S, Chung E R, Kim J H, et al. Posterior vertebral column    resection for severe spinal deformities. Spine 2005; 30 (14):    1682-87.-   13. Suk S, Chung E R, Lee S M, et al. Posterior vertebral column    resection in fixed lumbosacral deformity. Spine 2005; 30 (23):    E703-10.

1. A rod link reducer of a spinal fixation system comprising: a firstand a second spinal rod manipulator; a first spinal rod manipulatorjoint connected to the first spinal rod manipulator and a second spinalrod manipulator joint connected to the second spinal rod manipulator; afirst and a second translatable transverse shaft connected to the firstand second joints, respectively; and a universal reducer connected toboth the first and second translatable transverse shafts, wherein thereducer and the shafts provide movement and temporary fixation of aspine that has been manipulated into a final position during spinalsurgery.
 2. The reducer of claim 1, wherein the spinal rod manipulatoris further defined as comprising a handle and a rod attachment fixationpoint, wherein the rod attachment fixation point at least partiallysurrounds a rod with a semi-permanent fastener.
 3. The reducer of claim1, wherein the first, the second or both the first and secondtranslatable transverse shafts connects to the universal reducer and arecapable of sliding to increase or decrease the distance between thefirst and second joints.
 4. The reducer of claim 1, wherein theuniversal reducer comprises a ball joint, a universal joint, a pivot, aslot, a collar, a bearing, a dove-tail, a ball-joint, a gimbal, a level,or a sleeve that permits movement of the translatable transverse shaftsin two or more dimensions.
 5. The reducer of claim 1, wherein theuniversal reducer further comprises a fastener that semi-permanentlyfixes the position of the reducer in relation to the first, the secondor both translatable transverse shafts.
 6. The reducer of claim 1,wherein the first and second joints each comprise an independentfastener that semi-permanently fixes the relative position of the firstspinal rod manipulator to the first translatable transverse shaft, thesecond spinal rod manipulator to the second translatable transverseshaft or both the first and second spinal rod manipulator to the firstand second translatable transverse shafts, respectively.
 7. The reducerof claim 1, wherein the reducer comprises titanium, stainless steel,spring steel, aluminum, Niobium and alloys thereof, carbon fiber,ceramics, polymers, composites or combinations thereof.
 8. A method ofcorrecting a spinal deformity comprising: fastening two or more pediclescrew into two or more vertebra; interconnecting the pedicle screws withtwo or more temporary rods; connecting a of link reducer between thetemporary rods, the rod link reducer comprising: a first and a secondspinal rod manipulator; a first spinal rod manipulator joint connectedto the first spinal rod manipulator and a second spinal rod manipulatorjoint connected to the second spinal rod manipulator; a first and asecond translatable transverse shaft connected to the first and secondjoints, respectively; and a universal reducer connected to both thefirst and second translatable transverse shafts, wherein the reducer,the shafts and the linkers provide movement and temporary fixation of aspine that has been manipulated into a final position during spinalsurgery; correcting the position of the spine by manipulating thetemporary rods attached to the pedicle screws; interconnecting thepedicle screws with a permanent fixation rod; and removing the temporaryrod.
 9. The method of claim 8, wherein the pedicle screws comprise: abone fastener and a rod coupling head, the rod coupling head comprisinga lower and an upper rod coupling: the lower rod coupling comprising: alateral rod opening adapted to receive a permanent rod; an angled boreextends into the lateral rod opening; and a permanent rod fastener inthe angled bore to engage a permanent rod in the lateral rod opening;and a upper rod coupling comprising: an upper rod opening adapted toreceive a temporary rod, wherein the upper rod opening is formed toreceive a temporary rod fastener, wherein the upper rod coupling isdetachable from the lower rod coupling at a transition; and wherein atemporary rod is temporarily affixed into the upper rod opening during abone realignment and a permanent rod is positioned in the lateral rodopening and engaged by the permanent rod fastener upon final bonealignment.
 10. The method of claim 8, wherein the spinal rod manipulatoris further defined as comprising a handle and a rod attachment fixationpoint, wherein the rod attachment fixation point at least partiallysurrounds a rod with a semi-permanent fastener.
 11. The method of claim8, wherein the first, the second or both the first and secondtranslatable transverse shafts connects to the universal reducer and arecapable of sliding to increase or decrease the distance between thefirst and second joints.
 12. The method of claim 8, wherein theuniversal reducer comprises a ball joint, a universal joint, a pivot, aslot, a collar, a bearing, a dove-tail, a ball-joint, a gimbal, a level,or a sleeve that permits movement of the translatable transverse shaftsin two or more dimensions.
 13. The method of claim 8, wherein theuniversal reducer further comprises a fastener that semi-permanentlyfixes the position of the reducer in relation to the first, the secondor both translatable transverse shafts.
 14. The method of claim 8,wherein the first and second joints each comprise an independentfastener that semi-permanently fixes the relative position of the firstspinal rod manipulator to the first translatable transverse shaft, thesecond spinal rod manipulator to the second translatable transverseshaft or both the first and second spinal rod manipulator to the firstand second translatable transverse shafts, respectively.
 15. The methodof claim 8, wherein the reducer comprises titanium, stainless steel,spring steel, aluminum, Niobium and alloys thereof, carbon fiber,ceramics, polymers, composites or combinations thereof.
 16. A kitcomprising: a rod link reducer of a spinal fixation system comprising: afirst and a second spinal rod manipulator; a first spinal rodmanipulator joint connected to the first spinal rod manipulator and asecond spinal rod manipulator joint connected to the second spinal rodmanipulator; a first and a second translatable transverse shaftconnected to the first and second joints, respectively; and a universalreducer connected to both the first and second translatable transverseshafts, wherein the reducer, the shafts and the linkers provide movementand temporary fixation of a spine that has been manipulated into a finalposition during spinal surgery.
 17. The kit of claim 16, furthercomprising two or more pedicle screw into two or more vertebra, thepedicle screw comprising a bone fastener and a rod coupling head, therod coupling head comprising separate lower and upper lower rodcouplings: the lower rod coupling comprising: a lateral rod openingadapted to receive a permanent rod; an angled bore extends into thelateral rod opening; and a permanent rod fastener in the angled bore toengage a permanent rod in the lateral rod opening; and a upper rodcoupling comprising: an upper rod opening adapted to receive a temporaryrod, wherein the upper rod opening is formed to receive a temporary rodfastener; and two or more temporary rod fasteners.
 18. The kit of claim17, further comprising a permanent rod and a temporary rod.
 19. The kitof claim 17, further comprising one or more rod link reducers.
 20. Thekit of claim 17, further comprising one or more leverage handles adaptedto fit the first, the second or both spinal rod manipulators.
 21. Thekit of claim 17, further comprising two or more permanent rods, two ormore temporary rods, one or more rod link reducers, a plurality ofpedicle screws and one or more leverage handles.
 22. A rod link reducerof a spinal fixation system comprising: a first and a second spinalmanipulator, wherein each of the manipulators is adapted to attach to atemporary rod; a first spinal manipulator universal joint connected tothe first spinal manipulator and a second spinal manipulator universaljoint connected to the second spinal manipulator; a first and a secondtranslatable transverse shaft that connected to the first and seconduniversal joints, respectively; and a universal reducer connected to thefirst and second translatable transverse shafts between the first andsecond spinal manipulators, wherein the reducer and the shafts providemovement and temporary fixation of a spine that has been manipulatedinto a final position during spinal surgery.